Anchoring
How to Tell if Your Anchor Is Dragging (and What to Do)
Published · Last checked October 2026
To tell if your anchor is dragging, take two transits or compass bearings on fixed objects as soon as you are set, and check them regularly. Set a GPS anchor alarm with a radius a little larger than your swing. Signs of dragging include bearings changing steadily in one direction, a juddering chain, the boat lying beam-on to the wind, and neighbours getting closer. If you are dragging, start the engine and re-anchor or leave.
Check as soon as you anchor
Once the anchor is down and you have dug it in with gentle astern power, note your position. Take a transit (two fixed objects lined up, such as a beacon in front of a house) or two compass bearings on features on the beam. Write them down. If they stay put, apart from the swing of the boat, you are holding.
Signs your anchor is dragging
- Transits open or bearings change steadily in one direction, not just swinging back and forth.
- The GPS track shows a line moving downwind instead of a tidy arc.
- The chain judders or rumbles, felt with a hand or foot on it at the bow.
- The boat lies beam-on to the wind instead of head to wind.
- Depth changes in a way the tide does not explain.
- Other boats seem to be moving towards or away from you.
Anchor alarms and swing
Most chart plotters and phone apps have an anchor watch. Set the centre where the anchor is, not where the boat is, and a radius equal to your scope plus boat length plus a margin. Too tight and it beeps all night; too wide and it is useless.
| Swinging | Dragging | |
|---|---|---|
| Bearings | Move back and forth | Change steadily one way |
| GPS track | Arc or figure of eight | Line downwind |
| Chain | Quiet, comes taut and slack | Juddering |
| Boat heading | Roughly head to wind | Often beam-on |
What to do if you drag
- Wake the crew, start the engine and put the navigation lights or deck light on if dark.
- Motor gently towards the anchor to take load off the chain.
- If there is room, let out more chain; this sometimes lets the anchor reset.
- Otherwise, weigh anchor and re-anchor in better holding or with more scope, or move to a safer spot.
- If you are about to hit something and cannot motor clear, warn nearby boats on VHF and by sound, and call the coastguard if you are in danger.
Getting the scope right is covered in how much anchor chain to let out. Transits and bearings are taught in the position fixing lesson.